Investigators working for Independent Counsel Kenneth Starr have called two witnesses before a grand jury in Arkansas as they begin probing allegations that the prosecutor's top Whitewater witness received payments from conservative activists.

An Arkansas woman and her son who have alleged that witness David Hale received cash from people working for the conservative American Spectator magazine testified before a panel in Fort Smith, Ark., the woman's lawyer said.

The grand jury was already impaneled to hear cases at the federal court for the state's western district.

Caryn Mann and her son Joshua, both of Rogers, Ark., claimed that Mann's ex-boyfriend Parker Dozhier and others paid Hale and he gave them secret grand jury information about the Whitewater investigation. They allege Hale received a series of payments ranging from $40 to $500 each.

Starr hired former Justice Department watchdog Michael Shaheen to investigate the matter. As a measure of independence, Shaheen is using a staff outside of Starr's office and will report his findings to a panel of retired judges.

"Caryn has been contacted by the FBI and lawyers assigned to Shaheen's investigation," said her attorney, David Matthews. She and her son have testified before a grand jury, the lawyer said.

Dozhier worked for the American Spectator as part of its $1.7 million project to unearth information about Whitewater, which was funded by foundations controlled by conservative billionaire Richard Mellon Scaife.

Scaife's foundations have helped finance several projects criticizing or investigating President Clinton.

Dozhier has denied making payments to Hale.

Hale, a former judge and lender who said Clinton urged him to make an illegal loan to one of his Whitewater business partners, has also denied receiving any money from people working for the magazine.

Mann and her attorney declined to discuss her testimony or say when she testified. The grand jury met most recently for three days during the first week of August, a court official said. Shaheen could not be reached for comment.

Shaheen's investigators on Friday questioned Bill Watt, a Little Rock attorney who said Mann told him about the alleged payments in 1997. Watt, a former traffic judge who was named an unindicted co-conspirator in a Whitewater case, said an FBI agent, an IRS agent and an assistant U.S. attorney working for Shaheen questioned him for an hour about what Mann told him.

The publisher of the American Spectator said the magazine also had been contacted by the investigators.

"We have been cooperating with the investigation consistent with First Amendment principles," said publisher Terry Eastland. Eastland said an internal probe of the magazine's "Arkansas Project" has turned up no evidence of payments to Hale.